This segfault occuring only under valgrind,
in shell way, and in gdb way i have
Invalid bitcode signature
simple_scev_dynamic_array:
/home/willy/apollo/llvm/include/llvm/Support/ErrorOr.h:258: storage_type
*llvm::ErrorOr<llvm::Module *>::getStorage() [T = llvm::Module *]:
Assertion `!HasError && "Cannot get value when an error
exists!"' failed.
Command terminated by signal 6
this is the code I use:
long jitter(void* info, skeleton_pair *skeletons, long skeleton_size, param_t
params, long phi_state_size) {
InitializeNativeTarget();
InitializeNativeTargetAsmPrinter();
llvm::StringRef sr (skeletons[idx].jit_bytecode,
skeletons[idx].jit_bytecode_length);
if (sr.str()[0] == 'B')
std::cout << "B ok\n";
if (sr.str()[1] == 'C')
std::cout << "C ok\n";
if (sr.str()[2] == (char) 0xc0)
std::cout << "0xc0
ok\n";
if (sr.str()[3] == (char) 0xde)
std::cout << "0xde
ok\n";
llvm::MemoryBuffer* mbjit = llvm::MemoryBuffer::getMemBufferCopy (sr);
llvm::ErrorOr<llvm::Module*> ModuleOrErr = llvm::parseBitcodeFile (mbjit,
context);
if (llvm::error_code EC = ModuleOrErr.getError()) {
std::cout << ModuleOrErr.getError().message() << "\n";
}
Module* Mjit = ModuleOrErr.get();
std::string eeError;
ExecutionEngine* nee =
EngineBuilder(Mjit).setEngineKind(EngineKind::JIT).setUseMCJIT(true).setErrorStr(&eeError).create();
if (!nee) {
fprintf(stderr, "Could not create ExecutionEngine: %s\n",
eeError.c_str());
assert(false);
}
Function f = ret_fct(Mjit); // Function* ret_fct (Module*); return the
function we want to jit.
uint64_t f_ptr = nee->getFunctionAddress(f->getName());
long (*fjited)(param_t, phi_state_t, long, long, long, long)
= (long (*)(param_t, phi_state_t, long, long, long, long)) (intptr_t)f_ptr;
return fjited (params, phi_state, lower, upper, inst_outer, inst_inner);
}
Thanks,
--
Willy WOLFF
On 20 Mar 2014, at 00:37, Vikas Bhargava wrote:
> segmentation fault indicates memory corruption and it's hard to tell
without seeing the exact use of the APIs. If possible, please post a complete
program and gdb stack trace from the core file. If there are multiple threads
using the global variables, please let us know.
>
> FWIW, I have some tests to write llvm::Module to bitcode files and read
them back into llvm::Module and they work just fine with 3.4 (never tried with
tip).
>
> thx
> vikas.
> =======>
>
> On Wed, Mar 19, 2014 at 2:58 PM, Willy WOLFF <willy.wolff at
etu.unistra.fr> wrote:
> all of:
> ----
> // cout << "lsr: " <<
lsr << "\n";
> llvm::MemoryBuffer* mbjit >
llvm::MemoryBuffer::getMemBufferCopy (sr);
> ------
> string lsr = sr.str();
> // cout << "lsr: " <<
lsr << "\n";
> llvm::MemoryBuffer* mbjit >
llvm::MemoryBuffer::getMemBuffer (lsr);
> -------
> string lsr = sr.str();
> // cout << "lsr: " <<
lsr << "\n";
> llvm::MemoryBuffer* mbjit >
llvm::MemoryBuffer::getMemBufferCopy (lsr);
>
>
> have same result as invalid bit code.
> The result of valgrind, effectively, i have invalid reads in the
parseBitcodeFile:
>
> ==536== Conditional jump or move depends on uninitialised value(s)
> ==536== at 0x501FE3: llvm::BitstreamCursor::Read(unsigned int) (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== by 0x501A19:
llvm::BitcodeReader::ParseBitcodeInto(llvm::Module*) (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== by 0x50AEC8: llvm::getLazyBitcodeModule(llvm::MemoryBuffer*,
llvm::LLVMContext&) (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== by 0x50B295: llvm::parseBitcodeFile(llvm::MemoryBuffer*,
llvm::LLVMContext&) (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== by 0x4F1231: blah_runtime_hook (runtime.cpp:348)
> ==536== by 0x4F46C2: ??? (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== by 0x4F2B60: main (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536==
> ==536== Invalid read of size 8
> ==536== at 0x501FE8: llvm::BitstreamCursor::Read(unsigned int) (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== by 0x501A19:
llvm::BitcodeReader::ParseBitcodeInto(llvm::Module*) (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== by 0x50AEC8: llvm::getLazyBitcodeModule(llvm::MemoryBuffer*,
llvm::LLVMContext&) (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== by 0x50B295: llvm::parseBitcodeFile(llvm::MemoryBuffer*,
llvm::LLVMContext&) (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== by 0x4F1231: blah_runtime_hook (runtime.cpp:348)
> ==536== by 0x4F46C2: ??? (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== by 0x4F2B60: main (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== Address 0x0 is not stack'd, malloc'd or (recently)
free'd
> ==536==
> ==536==
> ==536== Process terminating with default action of signal 11 (SIGSEGV)
> ==536== Access not within mapped region at address 0x0
> ==536== at 0x501FE8: llvm::BitstreamCursor::Read(unsigned int) (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== by 0x501A19:
llvm::BitcodeReader::ParseBitcodeInto(llvm::Module*) (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== by 0x50AEC8: llvm::getLazyBitcodeModule(llvm::MemoryBuffer*,
llvm::LLVMContext&) (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== by 0x50B295: llvm::parseBitcodeFile(llvm::MemoryBuffer*,
llvm::LLVMContext&) (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== by 0x4F1231: blah_runtime_hook (runtime.cpp:348)
> ==536== by 0x4F46C2: ??? (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
> ==536== by 0x4F2B60: main (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>
>
>
> --
> Willy WOLFF
>
> On 19 Mar 2014, at 22:11, Vikas Bhargava wrote:
>
>> Hi Willy,
>> If the disassembly of the module works fine, then there is nothing
wrong with the module.
>>
>> Stream uses the memorybuffer that you pass in parseBitcodeFile. If what
Will is saying is true, there is something wrong with your code in
"3:", i.e.:
>>
>> MemoryBuffer* mbjit = MemoryBuffer::getMemBuffer (sr.str());
>> LLVMContext& context = getGlobalContext();
>> ErrorOr<Module*> ModuleOrErr = parseBitcodeFile (mbjit,
context);
>> if (error_code EC = ModuleOrErr.getError())
>> {
>> std::cout << ModuleOrErr.getError().
>> message() << "\n";
>> assert(false);
>> }
>>
>> Can you post how you modified it in your second reply? For debugging
purpose, you can simply use MemoryBuffer::getMemBufferCopy() and not worry about
validity of stringref or null-termination. Also, you can run your program
through valgrind and check for any invalid reads.
>>
>> HTH
>> Vikas.
>> ======>>
>>
>>
>> On Wed, Mar 19, 2014 at 10:32 AM, Willy WOLFF <willy.wolff at
etu.unistra.fr> wrote:
>> I mad the change, and still have the problem.
>>
>> I investigate more the source code of llvm.
>>
>> First, I change isRawBitcode function to print the content of the
parameter like this:
>> original:
http://llvm.org/docs/doxygen/html/ReaderWriter_8h_source.html#l00081
>>
>> inline bool isRawBitcode(const unsigned char *BufPtr,
>> const unsigned char *BufEnd) {
>> // These bytes sort of have a hidden message, but it's not in
>> // little-endian this time, and it's a little redundant.
>> errs()<< "isRawBitcode output:\n";
>> for (int i = 0; i < 4; i++)
>> errs() << BufPtr[i] << "\n";
>> if (BufPtr != BufEnd )
>> errs() << "BP != BE ok\n";
>> if (BufPtr[0] == 'B')
>> errs() << "B ok\n";
>> if (BufPtr[1] == 'C')
>> errs() << "C ok\n";
>> if (BufPtr[2] == 0xc0)
>> errs() << "0xc0 ok\n";
>> if (BufPtr[3] == 0xde)
>> errs() << "0xde ok\n";
>>
>> return BufPtr != BufEnd &&
>> BufPtr[0] == 'B' &&
>> BufPtr[1] == 'C' &&
>> BufPtr[2] == 0xc0 &&
>> BufPtr[3] == 0xde;
>> }
>>
>>
>> Second, I change ParseBitcodeInto as this:
>> original:
http://llvm.org/docs/doxygen/html/BitcodeReader_8cpp_source.html#l01971
>> ...
>> errs() << "parsebitcodeinto sniff the
signature\n";
>> uint32_t bvar = Stream.Read(8);
>> errs() << "B :" << bvar
<< "\n";
>> if (bvar != 'B') {
>> errs() << "B :" << bvar <<
"\n";
>> return Error(InvalidBitcodeSignature);
>> }
>>
>> if (Stream.Read(8) != 'C') {
>> errs() << "C\n";
>> return Error(InvalidBitcodeSignature);
>> }
>> if ( Stream.Read(8) != 0xc0 ) {
>> errs() << "0xc0\n";
>> return Error(InvalidBitcodeSignature);
>> }
>> if ( Stream.Read(8) != 0xde ) {
>> errs() << "0xde\n";
>> return Error(InvalidBitcodeSignature);
>> }
>> // if (Stream.Read(8) != 'B' ||
>> // Stream.Read(8) != 'C' ||
>> // Stream.Read(4) != 0x0 ||
>> // Stream.Read(4) != 0xC ||
>> // Stream.Read(4) != 0xE ||
>> // Stream.Read(4) != 0xD
>> // ) {
>> ...
>>
>>
>>
>> The output of the code is :
>>
>>
>> isRawBitcode output:
>> B
>> C
>>
>>
>> BP != BE ok
>>
>> B ok
>> C ok
>> 0xc0 ok
>> 0xde ok
>>
>> parsebitcodeinto sniff the signature
>> B :37
>> B :37
>>
>>
>>
>>
>> It's possible that Stream object is not correctly initialized?
>>
>>
>> On 03/13/2014 06:37 PM, Will Dietz wrote:
>> On Thu, Mar 13, 2014 at 9:02 AM, Willy WOLFF <willy.wolff at
etu.unistra.fr> wrote:
>> Hello,
>>
>> I having a weird problem while writing a bytecode module to a string,
>> and after read/parse it for unsing on a jit.
>>
>> I write a pass to export function to module, and put this module inside
>> a global variable.
>> I use WriteBitcodeToFile for this.
>> For debuging, after this write, I try to load the exported module with
>> parseBitcodeFile.
>> This two step works.
>>
>>
>>
>> After, while the compiled program is running, I try to read and parse
>> this global variable for jiting the function.
>>
>> 1) I read the global variable with
>> StringRef sr (gv, gv_length);
>>
>> 2) I manually test this bytecode by
>> (inspired by inline bool isRawBitcode(const unsigned char *BufPtr,
>> const unsigned char *BufEnd) at
>> http://llvm.org/docs/doxygen/html/ReaderWriter_8h_source.html#l00067)
>> if (sr.str()[0] == 'B')
>> std::cout << "B ok\n";
>> if (sr.str()[1] == 'C')
>> std::cout << "C ok\n";
>> if (sr.str()[2] == (char) 0xc0)
>> std::cout << "0xc0 ok\n";
>> if (sr.str()[3] == (char) 0xde)
>> std::cout << "0xde ok\n";
>>
>> 3) I try to parse the gv by
>> MemoryBuffer* mbjit = MemoryBuffer::getMemBuffer (sr.str());
>>
>> Not sure if this is your issue, but should be fixed anyway:
>>
>> The std::string created by "sr.str()" ends its lifetime in
this
>> statement, and MemoryBuffer for efficiency reasons
>> avoids copying data it doesn't have to (like StringRef) so will be
>> referencing the freed memory.
>>
>> To resolve this:
>> * Pass MemoryBuffer your StringRef directly
>> * Use getMemBufferCopy()
>> * Preserve the result of sr.str() into a stack variable and pass that
>> to getMemoryBuffer() instead.
>>
>> As a final note, check if your bitcode buffer "string" is
>> null-terminated or not. If not, be sure to be careful and
>> do things like informing MemoryBuffer that this is the case.
>>
>> Hope this helps,
>> ~Will
>>
>> LLVMContext& context = getGlobalContext();
>> ErrorOr<Module*> ModuleOrErr = parseBitcodeFile (mbjit,
context);
>> if (error_code EC = ModuleOrErr.getError())
>> {
>> std::cout << ModuleOrErr.getError().message() <<
"\n";
>> assert(false);
>> }
>>
>>
>>
>>
>> This is the execution result:
>> B ok
>> C ok
>> 0xc0 ok
>> 0xde ok
>> Invalid bitcode signature
>>
>>
>>
>> Ok is not working :/
>> But why ???
>>
>>
>>
>> For debuging, between 2) and 3), I export the readed module and write
to
>> a file on my hard drive,
>> and try llvm-dis, and the dissasembly of the module works.
>>
>> Wath's wrong? Any idea for solve this problem?
>>
>> Thanks you very much.
>>
>> Regards,
>> Willy
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
>
>
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The stack trace is:
(gdb) bt
#0 0x00000000004fa8c8 in llvm::BitstreamCursor::Read(unsigned int) ()
#1 0x00000000004fa1d2 in
llvm::BitcodeReader::ParseBitcodeInto(llvm::Module*) ()
#2 0x0000000000503ae9 in
llvm::getLazyBitcodeModule(llvm::MemoryBuffer*, llvm::LLVMContext&) ()
#3 0x0000000000503eb6 in llvm::parseBitcodeFile(llvm::MemoryBuffer*,
llvm::LLVMContext&) ()
#4 0x00000000004ec195 in jitter (skeletons=<optimized out>,
params=0x7fffffffdf40, phi_state=0x11adbc0, lower=0, upper=250,
inst_outer=8, inst_inner=<optimized out>)
at /home/willy/hello_stuff/with_apollo/simple_loop/runtime.cpp:263
#5 0x00000000004ec8fa in apollo_runtime_hook (info=<optimized out>,
skeletons=0xc8b1f0, skeleton_size=<optimized out>,
params=0x7fffffffdf40, phi_state_size=<optimized out>)
at /home/willy/hello_stuff/with_apollo/simple_loop/runtime.cpp:438
#6 0x00000000004ee753 in ?? ()
#7 0x00000000004ecbf1 in main (argc=<optimized out>, argv=<optimized
out>) at
/home/willy/hello_stuff/with_apollo/simple_loop/simple_scev_dynamic_array.c:84
On 03/20/2014 10:10 AM, Willy WOLFF wrote:> This segfault occuring only under valgrind,
> in shell way, and in gdb way i have
>
> Invalid bitcode signature
> simple_scev_dynamic_array:
> /home/willy/apollo/llvm/include/llvm/Support/ErrorOr.h:258: storage_type
> *llvm::ErrorOr<llvm::Module *>::getStorage() [T = llvm::Module *]:
> Assertion `!HasError && "Cannot get value when an error
exists!"' failed.
> Command terminated by signal 6
>
>
> this is the code I use:
>
>
> long jitter(void* info, skeleton_pair *skeletons, long skeleton_size,
> param_t params, long phi_state_size) {
> InitializeNativeTarget();
> InitializeNativeTargetAsmPrinter();
>
> llvm::StringRef sr (skeletons[idx].jit_bytecode,
> skeletons[idx].jit_bytecode_length);
>
> if (sr.str()[0] == 'B')
> std::cout << "B
ok\n";
> if (sr.str()[1] == 'C')
> std::cout << "C
ok\n";
> if (sr.str()[2] == (char) 0xc0)
> std::cout << "0xc0
ok\n";
> if (sr.str()[3] == (char) 0xde)
> std::cout << "0xde
ok\n";
> llvm::MemoryBuffer* mbjit = llvm::MemoryBuffer::getMemBufferCopy (sr);
>
> llvm::ErrorOr<llvm::Module*> ModuleOrErr = llvm::parseBitcodeFile
> (mbjit, context);
> if (llvm::error_code EC = ModuleOrErr.getError()) {
> std::cout << ModuleOrErr.getError().message() <<
"\n";
> }
>
> Module* Mjit = ModuleOrErr.get();
>
> std::string eeError;
> ExecutionEngine* nee >
EngineBuilder(Mjit).setEngineKind(EngineKind::JIT).setUseMCJIT(true).setErrorStr(&eeError).create();
> if (!nee) {
> fprintf(stderr, "Could not create ExecutionEngine: %s\n",
eeError.c_str());
> assert(false);
> }
>
> Function f = ret_fct(Mjit); // Function* ret_fct (Module*); return
> the function we want to jit.
> uint64_t f_ptr = nee->getFunctionAddress(f->getName());
>
> long (*fjited)(param_t, phi_state_t, long, long, long, long)
> = (long (*)(param_t, phi_state_t, long, long, long, long)) (intptr_t)f_ptr;
>
> returnfjited (params, phi_state, lower, upper, inst_outer, inst_inner);
> }
>
>
> Thanks,
> *--*
> *Willy WOLFF*
>
> On 20 Mar 2014, at 00:37, Vikas Bhargava wrote:
>
>> segmentation fault indicates memory corruption and it's hard to
tell
>> without seeing the exact use of the APIs. If possible, please post a
>> complete program and gdb stack trace from the core file. If there are
>> multiple threads using the global variables, please let us know.
>>
>> FWIW, I have some tests to write llvm::Module to bitcode files and
>> read them back into llvm::Module and they work just fine with 3.4
>> (never tried with tip).
>>
>> thx
>> vikas.
>> =======>>
>>
>> On Wed, Mar 19, 2014 at 2:58 PM, Willy WOLFF
>> <willy.wolff at etu.unistra.fr <mailto:willy.wolff at
etu.unistra.fr>> wrote:
>>
>> all of:
>> ----
>> // cout << "lsr: "
<< lsr << "\n";
>> llvm::MemoryBuffer* mbjit >>
>> llvm::MemoryBuffer::getMemBufferCopy (sr);
>> ------
>> string lsr = sr.str();
>> // cout << "lsr: "
<< lsr << "\n";
>> llvm::MemoryBuffer* mbjit >>
>> llvm::MemoryBuffer::getMemBuffer (lsr);
>> -------
>> string lsr = sr.str();
>> // cout << "lsr: "
<< lsr << "\n";
>> llvm::MemoryBuffer* mbjit >>
>> llvm::MemoryBuffer::getMemBufferCopy (lsr);
>>
>>
>> have same result as invalid bit code.
>> The result of valgrind, effectively, i have invalid reads in the
>> parseBitcodeFile:
>>
>> ==536== Conditional jump or move depends on uninitialised value(s)
>> ==536== at 0x501FE3: llvm::BitstreamCursor::Read(unsigned int)
>> (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== by 0x501A19:
>> llvm::BitcodeReader::ParseBitcodeInto(llvm::Module*) (in
>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== by 0x50AEC8:
>> llvm::getLazyBitcodeModule(llvm::MemoryBuffer*,
>> llvm::LLVMContext&) (in
>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== by 0x50B295:
>> llvm::parseBitcodeFile(llvm::MemoryBuffer*, llvm::LLVMContext&)
>> (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== by 0x4F1231: blah_runtime_hook (runtime.cpp:348)
>> ==536== by 0x4F46C2: ??? (in
>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== by 0x4F2B60: main (in
>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536=>> ==536== Invalid read of size 8
>> ==536== at 0x501FE8: llvm::BitstreamCursor::Read(unsigned int)
>> (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== by 0x501A19:
>> llvm::BitcodeReader::ParseBitcodeInto(llvm::Module*) (in
>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== by 0x50AEC8:
>> llvm::getLazyBitcodeModule(llvm::MemoryBuffer*,
>> llvm::LLVMContext&) (in
>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== by 0x50B295:
>> llvm::parseBitcodeFile(llvm::MemoryBuffer*, llvm::LLVMContext&)
>> (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== by 0x4F1231: blah_runtime_hook (runtime.cpp:348)
>> ==536== by 0x4F46C2: ??? (in
>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== by 0x4F2B60: main (in
>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== Address 0x0 is not stack'd, malloc'd or (recently)
free'd
>> ==536=>> ==536=>> ==536== Process terminating
with default action of signal 11 (SIGSEGV)
>> ==536== Access not within mapped region at address 0x0
>> ==536== at 0x501FE8: llvm::BitstreamCursor::Read(unsigned int)
>> (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== by 0x501A19:
>> llvm::BitcodeReader::ParseBitcodeInto(llvm::Module*) (in
>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== by 0x50AEC8:
>> llvm::getLazyBitcodeModule(llvm::MemoryBuffer*,
>> llvm::LLVMContext&) (in
>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== by 0x50B295:
>> llvm::parseBitcodeFile(llvm::MemoryBuffer*, llvm::LLVMContext&)
>> (in
/home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== by 0x4F1231: blah_runtime_hook (runtime.cpp:348)
>> ==536== by 0x4F46C2: ??? (in
>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>> ==536== by 0x4F2B60: main (in
>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array)
>>
>>
>>
>> *--*
>> *Willy WOLFF*
>>
>> On 19 Mar 2014, at 22:11, Vikas Bhargava wrote:
>>
>>> Hi Willy,
>>> If the disassembly of the module works fine, then there is
>>> nothing wrong with the module.
>>>
>>> Stream uses the memorybuffer that you pass in parseBitcodeFile.
>>> If what Will is saying is true, there is something wrong with
>>> your code in "3:", i.e.:
>>>
>>> MemoryBuffer* mbjit = MemoryBuffer::getMemBuffer (sr.str());
>>> LLVMContext& context = getGlobalContext();
>>> ErrorOr<Module*> ModuleOrErr = parseBitcodeFile (mbjit,
context);
>>> if (error_code EC = ModuleOrErr.getError())
>>> {
>>> std::cout << ModuleOrErr.getError().
>>> message() << "\n";
>>> assert(false);
>>> }
>>>
>>> Can you post how you modified it in your second reply? For
>>> debugging purpose, you can simply use
>>> MemoryBuffer::getMemBufferCopy() and not worry about validity
of
>>> stringref or null-termination. Also, you can run your program
>>> through valgrind and check for any invalid reads.
>>>
>>> HTH
>>> Vikas.
>>> ======>>>
>>>
>>>
>>> On Wed, Mar 19, 2014 at 10:32 AM, Willy WOLFF
>>> <willy.wolff at etu.unistra.fr <mailto:willy.wolff at
etu.unistra.fr>>
>>> wrote:
>>>
>>> I mad the change, and still have the problem.
>>>
>>> I investigate more the source code of llvm.
>>>
>>> First, I change isRawBitcode function to print the content
of
>>> the parameter like this:
>>> original:
>>>
http://llvm.org/docs/doxygen/__html/ReaderWriter_8h_source.__html#l00081
>>>
<http://llvm.org/docs/doxygen/html/ReaderWriter_8h_source.html#l00081>
>>>
>>> inline bool isRawBitcode(const unsigned char *BufPtr,
>>> const unsigned char *BufEnd) {
>>> // These bytes sort of have a hidden message, but
it's not in
>>> // little-endian this time, and it's a little
redundant.
>>> errs()<< "isRawBitcode
output:\n";
>>> for (int i = 0; i < 4; i++)
>>> errs() << BufPtr[i] <<
"\n";
>>> if (BufPtr != BufEnd )
>>> errs() << "BP != BE ok\n";
>>> if (BufPtr[0] == 'B')
>>> errs() << "B ok\n";
>>> if (BufPtr[1] == 'C')
>>> errs() << "C ok\n";
>>> if (BufPtr[2] == 0xc0)
>>> errs() << "0xc0 ok\n";
>>> if (BufPtr[3] == 0xde)
>>> errs() << "0xde ok\n";
>>>
>>> return BufPtr != BufEnd &&
>>> BufPtr[0] == 'B' &&
>>> BufPtr[1] == 'C' &&
>>> BufPtr[2] == 0xc0 &&
>>> BufPtr[3] == 0xde;
>>> }
>>>
>>>
>>> Second, I change ParseBitcodeInto as this:
>>> original:
>>>
http://llvm.org/docs/doxygen/__html/BitcodeReader_8cpp___source.html#l01971
>>>
<http://llvm.org/docs/doxygen/html/BitcodeReader_8cpp_source.html#l01971>
>>> ...
>>> errs() << "parsebitcodeinto sniff the
signature\n";
>>> uint32_t bvar = Stream.Read(8);
>>> errs() << "B :"
<< bvar << "\n";
>>> if (bvar != 'B') {
>>> errs() << "B :" <<
bvar << "\n";
>>> return Error(InvalidBitcodeSignature)__;
>>> }
>>>
>>> if (Stream.Read(8) != 'C') {
>>> errs() << "C\n";
>>> return Error(InvalidBitcodeSignature)__;
>>> }
>>> if ( Stream.Read(8) != 0xc0 ) {
>>> errs() << "0xc0\n";
>>> return Error(InvalidBitcodeSignature)__;
>>> }
>>> if ( Stream.Read(8) != 0xde ) {
>>> errs() << "0xde\n";
>>> return Error(InvalidBitcodeSignature)__;
>>> }
>>> // if (Stream.Read(8) != 'B' ||
>>> // Stream.Read(8) != 'C' ||
>>> // Stream.Read(4) != 0x0 ||
>>> // Stream.Read(4) != 0xC ||
>>> // Stream.Read(4) != 0xE ||
>>> // Stream.Read(4) != 0xD
>>> // ) {
>>> ...
>>>
>>>
>>>
>>> The output of the code is :
>>>
>>>
>>> isRawBitcode output:
>>> B
>>> C
>>>
>>>
>>> BP != BE ok
>>>
>>> B ok
>>> C ok
>>> 0xc0 ok
>>> 0xde ok
>>>
>>> parsebitcodeinto sniff the signature
>>> B :37
>>> B :37
>>>
>>>
>>>
>>>
>>> It's possible that Stream object is not correctly
initialized?
>>>
>>>
>>> On 03/13/2014 06:37 PM, Will Dietz wrote:
>>>
>>> On Thu, Mar 13, 2014 at 9:02 AM, Willy WOLFF
>>> <willy.wolff at etu.unistra.fr
>>> <mailto:willy.wolff at etu.unistra.fr>> wrote:
>>>
>>> Hello,
>>>
>>> I having a weird problem while writing a bytecode
>>> module to a string,
>>> and after read/parse it for unsing on a jit.
>>>
>>> I write a pass to export function to module, and
put
>>> this module inside
>>> a global variable.
>>> I use WriteBitcodeToFile for this.
>>> For debuging, after this write, I try to load the
>>> exported module with
>>> parseBitcodeFile.
>>> This two step works.
>>>
>>>
>>>
>>> After, while the compiled program is running, I try
>>> to read and parse
>>> this global variable for jiting the function.
>>>
>>> 1) I read the global variable with
>>> StringRef sr (gv, gv_length);
>>>
>>> 2) I manually test this bytecode by
>>> (inspired by inline bool isRawBitcode(const
unsigned
>>> char *BufPtr,
>>> const unsigned char *BufEnd) at
>>>
http://llvm.org/docs/doxygen/__html/ReaderWriter_8h_source.__html#l00067
>>>
<http://llvm.org/docs/doxygen/html/ReaderWriter_8h_source.html#l00067>)
>>> if (sr.str()[0] == 'B')
>>> std::cout << "B ok\n";
>>> if (sr.str()[1] == 'C')
>>> std::cout << "C ok\n";
>>> if (sr.str()[2] == (char) 0xc0)
>>> std::cout << "0xc0 ok\n";
>>> if (sr.str()[3] == (char) 0xde)
>>> std::cout << "0xde ok\n";
>>>
>>> 3) I try to parse the gv by
>>> MemoryBuffer* mbjit = MemoryBuffer::getMemBuffer
>>> (sr.str());
>>>
>>>
>>> Not sure if this is your issue, but should be fixed
anyway:
>>>
>>> The std::string created by "sr.str()" ends
its lifetime
>>> in this
>>> statement, and MemoryBuffer for efficiency reasons
>>> avoids copying data it doesn't have to (like
StringRef)
>>> so will be
>>> referencing the freed memory.
>>>
>>> To resolve this:
>>> * Pass MemoryBuffer your StringRef directly
>>> * Use getMemBufferCopy()
>>> * Preserve the result of sr.str() into a stack variable
>>> and pass that
>>> to getMemoryBuffer() instead.
>>>
>>> As a final note, check if your bitcode buffer
"string" is
>>> null-terminated or not. If not, be sure to be careful
and
>>> do things like informing MemoryBuffer that this is the
case.
>>>
>>> Hope this helps,
>>> ~Will
>>>
>>> LLVMContext& context = getGlobalContext();
>>> ErrorOr<Module*> ModuleOrErr =
parseBitcodeFile
>>> (mbjit, context);
>>> if (error_code EC = ModuleOrErr.getError())
>>> {
>>> std::cout <<
ModuleOrErr.getError().__message()
>>> << "\n";
>>> assert(false);
>>> }
>>>
>>>
>>>
>>>
>>> This is the execution result:
>>> B ok
>>> C ok
>>> 0xc0 ok
>>> 0xde ok
>>> Invalid bitcode signature
>>>
>>>
>>>
>>> Ok is not working :/
>>> But why ???
>>>
>>>
>>>
>>> For debuging, between 2) and 3), I export the
readed
>>> module and write to
>>> a file on my hard drive,
>>> and try llvm-dis, and the dissasembly of the module
>>> works.
>>>
>>> Wath's wrong? Any idea for solve this problem?
>>>
>>> Thanks you very much.
>>>
>>> Regards,
>>> Willy
>>> _________________________________________________
>>> LLVM Developers mailing list
>>> LLVMdev at cs.uiuc.edu <mailto:LLVMdev at
cs.uiuc.edu>
>>> http://llvm.cs.uiuc.edu
<http://llvm.cs.uiuc.edu/>
>>> http://lists.cs.uiuc.edu/__mailman/listinfo/llvmdev
>>>
<http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev>
>>>
>>> _________________________________________________
>>> LLVM Developers mailing list
>>> LLVMdev at cs.uiuc.edu <mailto:LLVMdev at
cs.uiuc.edu>
>>> http://llvm.cs.uiuc.edu <http://llvm.cs.uiuc.edu/>
>>> http://lists.cs.uiuc.edu/__mailman/listinfo/llvmdev
>>> <http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev>
>>>
>>>
>>
>>
>
>
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
Vikas Bhargava
2014-Mar-20 21:32 UTC
[LLVMdev] load bytecode from string for jiting problem
Hello Willy, Here is the dump from one of my bitcode files: 0000000 42 43 c0 de 21 0c 00 00 25 05 00 00 0b 82 20 00 As expected, 0x42 (= B), 0x43 (= C), xc0 and 0xde are in correct order. In your case, the first byte is read as 37 (= 0x25). I wonder why? When you check the bytes yourself, you get expected results. When the same bytes are read from Stream object, you get a different result (maybe garbage). I would suggest that you put a watchpoint on mbjit->getBufferStart() and single step your program to make sure it is not freed, over written somewhere. thx Vikas. ====== On Thu, Mar 20, 2014 at 7:50 AM, Willy WOLFF <willy.wolff at etu.unistra.fr>wrote:> The stack trace is: > (gdb) bt > #0 0x00000000004fa8c8 in llvm::BitstreamCursor::Read(unsigned int) () > #1 0x00000000004fa1d2 in llvm::BitcodeReader:: > ParseBitcodeInto(llvm::Module*) () > #2 0x0000000000503ae9 in llvm::getLazyBitcodeModule(llvm::MemoryBuffer*, > llvm::LLVMContext&) () > #3 0x0000000000503eb6 in llvm::parseBitcodeFile(llvm::MemoryBuffer*, > llvm::LLVMContext&) () > #4 0x00000000004ec195 in jitter (skeletons=<optimized out>, > params=0x7fffffffdf40, phi_state=0x11adbc0, lower=0, upper=250, > inst_outer=8, inst_inner=<optimized out>) > at /home/willy/hello_stuff/with_apollo/simple_loop/runtime.cpp:263 > #5 0x00000000004ec8fa in apollo_runtime_hook (info=<optimized out>, > skeletons=0xc8b1f0, skeleton_size=<optimized out>, params=0x7fffffffdf40, > phi_state_size=<optimized out>) > at /home/willy/hello_stuff/with_apollo/simple_loop/runtime.cpp:438 > #6 0x00000000004ee753 in ?? () > #7 0x00000000004ecbf1 in main (argc=<optimized out>, argv=<optimized > out>) at /home/willy/hello_stuff/with_apollo/simple_loop/simple_ > scev_dynamic_array.c:84 > > > > > On 03/20/2014 10:10 AM, Willy WOLFF wrote: > >> This segfault occuring only under valgrind, >> in shell way, and in gdb way i have >> >> Invalid bitcode signature >> simple_scev_dynamic_array: >> /home/willy/apollo/llvm/include/llvm/Support/ErrorOr.h:258: storage_type >> *llvm::ErrorOr<llvm::Module *>::getStorage() [T = llvm::Module *]: >> Assertion `!HasError && "Cannot get value when an error exists!"' failed. >> Command terminated by signal 6 >> >> >> this is the code I use: >> >> >> long jitter(void* info, skeleton_pair *skeletons, long skeleton_size, >> param_t params, long phi_state_size) { >> InitializeNativeTarget(); >> InitializeNativeTargetAsmPrinter(); >> >> llvm::StringRef sr (skeletons[idx].jit_bytecode, >> skeletons[idx].jit_bytecode_length); >> >> if (sr.str()[0] == 'B') >> std::cout << "B ok\n"; >> if (sr.str()[1] == 'C') >> std::cout << "C ok\n"; >> if (sr.str()[2] == (char) 0xc0) >> std::cout << "0xc0 ok\n"; >> if (sr.str()[3] == (char) 0xde) >> std::cout << "0xde ok\n"; >> llvm::MemoryBuffer* mbjit = llvm::MemoryBuffer::getMemBufferCopy (sr); >> >> llvm::ErrorOr<llvm::Module*> ModuleOrErr = llvm::parseBitcodeFile >> (mbjit, context); >> if (llvm::error_code EC = ModuleOrErr.getError()) { >> std::cout << ModuleOrErr.getError().message() << "\n"; >> } >> >> Module* Mjit = ModuleOrErr.get(); >> >> std::string eeError; >> ExecutionEngine* nee >> EngineBuilder(Mjit).setEngineKind(EngineKind::JIT).setUseMCJIT(true). >> setErrorStr(&eeError).create(); >> if (!nee) { >> fprintf(stderr, "Could not create ExecutionEngine: %s\n", >> eeError.c_str()); >> assert(false); >> } >> >> Function f = ret_fct(Mjit); // Function* ret_fct (Module*); return >> the function we want to jit. >> uint64_t f_ptr = nee->getFunctionAddress(f->getName()); >> >> long (*fjited)(param_t, phi_state_t, long, long, long, long) >> = (long (*)(param_t, phi_state_t, long, long, long, long)) >> (intptr_t)f_ptr; >> >> returnfjited (params, phi_state, lower, upper, inst_outer, inst_inner); >> } >> >> >> Thanks, >> *--* >> *Willy WOLFF* >> >> >> On 20 Mar 2014, at 00:37, Vikas Bhargava wrote: >> >> segmentation fault indicates memory corruption and it's hard to tell >>> without seeing the exact use of the APIs. If possible, please post a >>> complete program and gdb stack trace from the core file. If there are >>> multiple threads using the global variables, please let us know. >>> >>> FWIW, I have some tests to write llvm::Module to bitcode files and >>> read them back into llvm::Module and they work just fine with 3.4 >>> (never tried with tip). >>> >>> thx >>> vikas. >>> =======>>> >>> >>> On Wed, Mar 19, 2014 at 2:58 PM, Willy WOLFF >>> <willy.wolff at etu.unistra.fr <mailto:willy.wolff at etu.unistra.fr>> wrote: >>> >>> all of: >>> ---- >>> // cout << "lsr: " << lsr << "\n"; >>> llvm::MemoryBuffer* mbjit >>> >>> llvm::MemoryBuffer::getMemBufferCopy (sr); >>> ------ >>> string lsr = sr.str(); >>> // cout << "lsr: " << lsr << "\n"; >>> llvm::MemoryBuffer* mbjit >>> >>> llvm::MemoryBuffer::getMemBuffer (lsr); >>> ------- >>> string lsr = sr.str(); >>> // cout << "lsr: " << lsr << "\n"; >>> llvm::MemoryBuffer* mbjit >>> >>> llvm::MemoryBuffer::getMemBufferCopy (lsr); >>> >>> >>> have same result as invalid bit code. >>> The result of valgrind, effectively, i have invalid reads in the >>> parseBitcodeFile: >>> >>> ==536== Conditional jump or move depends on uninitialised value(s) >>> ==536== at 0x501FE3: llvm::BitstreamCursor::Read(unsigned int) >>> (in /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== by 0x501A19: >>> llvm::BitcodeReader::ParseBitcodeInto(llvm::Module*) (in >>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== by 0x50AEC8: >>> llvm::getLazyBitcodeModule(llvm::MemoryBuffer*, >>> llvm::LLVMContext&) (in >>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== by 0x50B295: >>> llvm::parseBitcodeFile(llvm::MemoryBuffer*, llvm::LLVMContext&) >>> (in /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== by 0x4F1231: blah_runtime_hook (runtime.cpp:348) >>> ==536== by 0x4F46C2: ??? (in >>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== by 0x4F2B60: main (in >>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536=>>> ==536== Invalid read of size 8 >>> ==536== at 0x501FE8: llvm::BitstreamCursor::Read(unsigned int) >>> (in /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== by 0x501A19: >>> llvm::BitcodeReader::ParseBitcodeInto(llvm::Module*) (in >>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== by 0x50AEC8: >>> llvm::getLazyBitcodeModule(llvm::MemoryBuffer*, >>> llvm::LLVMContext&) (in >>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== by 0x50B295: >>> llvm::parseBitcodeFile(llvm::MemoryBuffer*, llvm::LLVMContext&) >>> (in /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== by 0x4F1231: blah_runtime_hook (runtime.cpp:348) >>> ==536== by 0x4F46C2: ??? (in >>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== by 0x4F2B60: main (in >>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== Address 0x0 is not stack'd, malloc'd or (recently) free'd >>> ==536=>>> ==536=>>> ==536== Process terminating with default action of signal 11 >>> (SIGSEGV) >>> ==536== Access not within mapped region at address 0x0 >>> ==536== at 0x501FE8: llvm::BitstreamCursor::Read(unsigned int) >>> (in /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== by 0x501A19: >>> llvm::BitcodeReader::ParseBitcodeInto(llvm::Module*) (in >>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== by 0x50AEC8: >>> llvm::getLazyBitcodeModule(llvm::MemoryBuffer*, >>> llvm::LLVMContext&) (in >>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== by 0x50B295: >>> llvm::parseBitcodeFile(llvm::MemoryBuffer*, llvm::LLVMContext&) >>> (in /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== by 0x4F1231: blah_runtime_hook (runtime.cpp:348) >>> ==536== by 0x4F46C2: ??? (in >>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> ==536== by 0x4F2B60: main (in >>> /home/willy/blah_test_script/new_blah/simple_scev_dynamic_array) >>> >>> >>> >>> *--* >>> *Willy WOLFF* >>> >>> >>> On 19 Mar 2014, at 22:11, Vikas Bhargava wrote: >>> >>> Hi Willy, >>>> If the disassembly of the module works fine, then there is >>>> nothing wrong with the module. >>>> >>>> Stream uses the memorybuffer that you pass in parseBitcodeFile. >>>> If what Will is saying is true, there is something wrong with >>>> your code in "3:", i.e.: >>>> >>>> MemoryBuffer* mbjit = MemoryBuffer::getMemBuffer (sr.str()); >>>> LLVMContext& context = getGlobalContext(); >>>> ErrorOr<Module*> ModuleOrErr = parseBitcodeFile (mbjit, context); >>>> if (error_code EC = ModuleOrErr.getError()) >>>> { >>>> std::cout << ModuleOrErr.getError(). >>>> message() << "\n"; >>>> assert(false); >>>> } >>>> >>>> Can you post how you modified it in your second reply? For >>>> debugging purpose, you can simply use >>>> MemoryBuffer::getMemBufferCopy() and not worry about validity of >>>> stringref or null-termination. Also, you can run your program >>>> through valgrind and check for any invalid reads. >>>> >>>> HTH >>>> Vikas. >>>> ======>>>> >>>> >>>> >>>> On Wed, Mar 19, 2014 at 10:32 AM, Willy WOLFF >>>> <willy.wolff at etu.unistra.fr <mailto:willy.wolff at etu.unistra.fr>> >>>> >>>> wrote: >>>> >>>> I mad the change, and still have the problem. >>>> >>>> I investigate more the source code of llvm. >>>> >>>> First, I change isRawBitcode function to print the content of >>>> the parameter like this: >>>> original: >>>> http://llvm.org/docs/doxygen/__html/ReaderWriter_8h_source._ >>>> _html#l00081 >>>> >>>> <http://llvm.org/docs/doxygen/html/ReaderWriter_8h_source. >>>> html#l00081> >>>> >>>> inline bool isRawBitcode(const unsigned char *BufPtr, >>>> const unsigned char *BufEnd) { >>>> // These bytes sort of have a hidden message, but it's not >>>> in >>>> // little-endian this time, and it's a little redundant. >>>> errs()<< "isRawBitcode output:\n"; >>>> for (int i = 0; i < 4; i++) >>>> errs() << BufPtr[i] << "\n"; >>>> if (BufPtr != BufEnd ) >>>> errs() << "BP != BE ok\n"; >>>> if (BufPtr[0] == 'B') >>>> errs() << "B ok\n"; >>>> if (BufPtr[1] == 'C') >>>> errs() << "C ok\n"; >>>> if (BufPtr[2] == 0xc0) >>>> errs() << "0xc0 ok\n"; >>>> if (BufPtr[3] == 0xde) >>>> errs() << "0xde ok\n"; >>>> >>>> return BufPtr != BufEnd && >>>> BufPtr[0] == 'B' && >>>> BufPtr[1] == 'C' && >>>> BufPtr[2] == 0xc0 && >>>> BufPtr[3] == 0xde; >>>> } >>>> >>>> >>>> Second, I change ParseBitcodeInto as this: >>>> original: >>>> http://llvm.org/docs/doxygen/__html/BitcodeReader_8cpp___ >>>> source.html#l01971 >>>> >>>> <http://llvm.org/docs/doxygen/html/BitcodeReader_8cpp_ >>>> source.html#l01971> >>>> ... >>>> errs() << "parsebitcodeinto sniff the signature\n"; >>>> uint32_t bvar = Stream.Read(8); >>>> errs() << "B :" << bvar << "\n"; >>>> if (bvar != 'B') { >>>> errs() << "B :" << bvar << "\n"; >>>> return Error(InvalidBitcodeSignature)__; >>>> >>>> } >>>> >>>> if (Stream.Read(8) != 'C') { >>>> errs() << "C\n"; >>>> return Error(InvalidBitcodeSignature)__; >>>> >>>> } >>>> if ( Stream.Read(8) != 0xc0 ) { >>>> errs() << "0xc0\n"; >>>> return Error(InvalidBitcodeSignature)__; >>>> >>>> } >>>> if ( Stream.Read(8) != 0xde ) { >>>> errs() << "0xde\n"; >>>> return Error(InvalidBitcodeSignature)__; >>>> >>>> } >>>> // if (Stream.Read(8) != 'B' || >>>> // Stream.Read(8) != 'C' || >>>> // Stream.Read(4) != 0x0 || >>>> // Stream.Read(4) != 0xC || >>>> // Stream.Read(4) != 0xE || >>>> // Stream.Read(4) != 0xD >>>> // ) { >>>> ... >>>> >>>> >>>> >>>> The output of the code is : >>>> >>>> >>>> isRawBitcode output: >>>> B >>>> C >>>> >>>> >>>> BP != BE ok >>>> >>>> B ok >>>> C ok >>>> 0xc0 ok >>>> 0xde ok >>>> >>>> parsebitcodeinto sniff the signature >>>> B :37 >>>> B :37 >>>> >>>> >>>> >>>> >>>> It's possible that Stream object is not correctly initialized? >>>> >>>> >>>> On 03/13/2014 06:37 PM, Will Dietz wrote: >>>> >>>> On Thu, Mar 13, 2014 at 9:02 AM, Willy WOLFF >>>> <willy.wolff at etu.unistra.fr >>>> <mailto:willy.wolff at etu.unistra.fr>> wrote: >>>> >>>> Hello, >>>> >>>> I having a weird problem while writing a bytecode >>>> module to a string, >>>> and after read/parse it for unsing on a jit. >>>> >>>> I write a pass to export function to module, and put >>>> this module inside >>>> a global variable. >>>> I use WriteBitcodeToFile for this. >>>> For debuging, after this write, I try to load the >>>> exported module with >>>> parseBitcodeFile. >>>> This two step works. >>>> >>>> >>>> >>>> After, while the compiled program is running, I try >>>> to read and parse >>>> this global variable for jiting the function. >>>> >>>> 1) I read the global variable with >>>> StringRef sr (gv, gv_length); >>>> >>>> 2) I manually test this bytecode by >>>> (inspired by inline bool isRawBitcode(const unsigned >>>> char *BufPtr, >>>> const unsigned char *BufEnd) at >>>> http://llvm.org/docs/doxygen/_ >>>> _html/ReaderWriter_8h_source.__html#l00067 >>>> <http://llvm.org/docs/doxygen/ >>>> html/ReaderWriter_8h_source.html#l00067>) >>>> >>>> if (sr.str()[0] == 'B') >>>> std::cout << "B ok\n"; >>>> if (sr.str()[1] == 'C') >>>> std::cout << "C ok\n"; >>>> if (sr.str()[2] == (char) 0xc0) >>>> std::cout << "0xc0 ok\n"; >>>> if (sr.str()[3] == (char) 0xde) >>>> std::cout << "0xde ok\n"; >>>> >>>> 3) I try to parse the gv by >>>> MemoryBuffer* mbjit = MemoryBuffer::getMemBuffer >>>> (sr.str()); >>>> >>>> >>>> Not sure if this is your issue, but should be fixed anyway: >>>> >>>> The std::string created by "sr.str()" ends its lifetime >>>> in this >>>> statement, and MemoryBuffer for efficiency reasons >>>> avoids copying data it doesn't have to (like StringRef) >>>> so will be >>>> referencing the freed memory. >>>> >>>> To resolve this: >>>> * Pass MemoryBuffer your StringRef directly >>>> * Use getMemBufferCopy() >>>> * Preserve the result of sr.str() into a stack variable >>>> and pass that >>>> to getMemoryBuffer() instead. >>>> >>>> As a final note, check if your bitcode buffer "string" is >>>> null-terminated or not. If not, be sure to be careful and >>>> do things like informing MemoryBuffer that this is the case. >>>> >>>> Hope this helps, >>>> ~Will >>>> >>>> LLVMContext& context = getGlobalContext(); >>>> ErrorOr<Module*> ModuleOrErr = parseBitcodeFile >>>> (mbjit, context); >>>> if (error_code EC = ModuleOrErr.getError()) >>>> { >>>> std::cout << ModuleOrErr.getError().__message() >>>> >>>> << "\n"; >>>> assert(false); >>>> } >>>> >>>> >>>> >>>> >>>> This is the execution result: >>>> B ok >>>> C ok >>>> 0xc0 ok >>>> 0xde ok >>>> Invalid bitcode signature >>>> >>>> >>>> >>>> Ok is not working :/ >>>> But why ??? >>>> >>>> >>>> >>>> For debuging, between 2) and 3), I export the readed >>>> module and write to >>>> a file on my hard drive, >>>> and try llvm-dis, and the dissasembly of the module >>>> works. >>>> >>>> Wath's wrong? Any idea for solve this problem? >>>> >>>> Thanks you very much. >>>> >>>> Regards, >>>> Willy >>>> _________________________________________________ >>>> LLVM Developers mailing list >>>> LLVMdev at cs.uiuc.edu <mailto:LLVMdev at cs.uiuc.edu> >>>> http://llvm.cs.uiuc.edu <http://llvm.cs.uiuc.edu/> >>>> http://lists.cs.uiuc.edu/__mailman/listinfo/llvmdev >>>> <http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev> >>>> >>>> _________________________________________________ >>>> LLVM Developers mailing list >>>> LLVMdev at cs.uiuc.edu <mailto:LLVMdev at cs.uiuc.edu> >>>> http://llvm.cs.uiuc.edu <http://llvm.cs.uiuc.edu/> >>>> http://lists.cs.uiuc.edu/__mailman/listinfo/llvmdev >>>> <http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev> >>>> >>>> >>>> >>> >>> >> >> >> _______________________________________________ >> LLVM Developers mailing list >> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >> >>-------------- next part -------------- An HTML attachment was scrubbed... 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Apparently Analagous Threads
- [LLVMdev] load bytecode from string for jiting problem
- [LLVMdev] load bytecode from string for jiting problem
- [LLVMdev] load bytecode from string for jiting problem
- [LLVMdev] load bytecode from string for jiting problem
- End-to-end -fembed-bitcode .llvmbc and .llvmcmd